a parallelogram has a base of 3 feet and a height of 5 feet. The base and height will each be doubled. Will the area also be doubled

No, doubling the base and height would actually quadruple the area,

Step-by-step explanation:

With the original measurements of b = 3 ft and h = 5 ft,

b x h = A

(3) x (5) = 15 ft

So lets say we doubled the factors:

(2) (3) x (2) (5) = A

We would end up with 60 feet, four times that of 15.

(6) x (10) = 60 ft